In the electronic, micro-electronics and computer industries it has been found that surface mounting of chip carrier packages and other similar components on printed circuit boards or other components will not withstand thermal cycling and other stresses to which the resulting assemblies are subjected during use. Therefore, it has become desirable to replace surface mounting by connecting one electronic component to another or to a circuit board using elongated joint-forming materials which will provide sufficient flexibility to enable the assembly to withstand thermal cycles and other stresses encountered during use. In commonly assigned U.S. patent applications Ser. Nos. 509,684 filed June 30, 1983 and 610,077 filed May 14, 1984, and in U.K. patent application No. 2,142,568, the disclosures of which are incorporated herein by reference, there are disclosed devices for providing such interconnection of electronic components using elongated joints between electronic components in an electronic assembly. These devices comprise a retaining member having apertures therein corresponding to the pre-selected points of interconnection and electrically conductive joint-forming material disposed in those apertures. The joint-forming material is an elongate member which can be attached to one electronic component or can be attached simultaneously to opposing electronic components thereby providing an elongate interconnect between the components which will withstand thermal cycles and other stresses. In a typical embodiment, the interconnect device contains columns of solder in the apertures of the retaining member. After the solder columns have been attached to one component or assembled between electronic components, it is frequently desirable to remove the retaining member. It has been recognized that it is desirable that the retaining member be dissolvable so that it can be removed after the joint-forming preforms, such as the solder columns, have been soldered into place on the electronic component.
It is an object of this invention to provide an improved retaining member which is dissolvable or removable in water. It is a further object of this invention to provide a retaining member which will provide sufficient strength and stability to provide for accurate placement of the joint-forming preforms, which will withstand soldering temperatures, and which is removable with water in a relatively short period of time.